When I introduce a local scope to make sure the gFBO Graphics object’s lifetime ends before I draw the image, I get an invalid operation error from OpenGL.
GL_INVALID_OPERATION error generated. Target buffer must be bound and not overlapped with mapping range.
I updated the working example to include the different cases that I tried, see GLComponent.cc:79 for the enum that switches between the drawing modes. Directly rendering to screen works, drawing into the Image with OpenGLImageType in two different ways behaves as described above (i.e. seeing the whole output only when using a transparency layer), drawing the image after the Graphics object lifetime ends leads to GL_INVALID_OPERATION.